It seems that levitation without contact is no longer just a cool illusion trick performed by magicians. Scientists at the Laboratory of Thermodynamics in Emerging Technologies in Zurich, Switzerland, have successfully levitated small objects using only sound waves.
Acoustic levitation is better than magnetic levitation in that it can be used on any object, not just materials that are magnetic. The only limitation with acoustic levitation is that the object's diameter must correspond to half the wavelength of the acoustic waves. Although acoustic levitation has been performed before, this new method allows researchers to have full control over an object's movement with a precision not seen in previous studies. With this new technique, the effect is created by static waves that are held in place by a reflector that bounces the wave back upon itself. This causes interference and creates a consistent upwards pressure that can cancel out the effect of gravity on an object placed within its field.
This research means that with enough power, anything could be possibly levitated, even humans. The power required for human levitation, though, would have to be immense, and it's not exactly a guarantee that the human body could survive such forces. The technology needs to be refined in order to prevent a body from exploding (ouch) or serious internal bleeding. The power involved also limits the reality of levitating heavier items, such as a human body. Needless to say, the standard warning applies: do not try this at home.
This new development could be useful on a smaller scale, though. As many biological and chemical processes can be disrupted by contact with a surface, acoustic levitation could provide a solution for working with such materials.